Then, suddenly, the dirigible shuddered, as if a great weight had fallen against it.

Sam and Itharquell clung to each other as the dirigible shuddered around them. Itharquell twisted a stem and the screen showed a rear view, blue tunnel walls whizzing past. And crawling along the ridged green back of the dirigible was a six-legged orange-bodied Ruin, tentacles thrashing. It was punching holes in the back of the dirigible, sawing its way through the pithy skin with its legs. Another appeared, and then another, crawling along the back of the dirigible.

Itharquell began hooting in panic.

'Try to shake them off,' urged Sam. 'You know, smash them against the roof of the cavern.'

The controls aren't responding. The Ruin must have severed the spinal cord. It would have been better if we had given ourselves up to the Blight.

'Rubbish,' said Sam, her insides turning to ice nonetheless. There was a crash from behind them, and Sam turned to see a thick spiderlike leg break through the ceiling, questing about, a six-spiked 'hand' at the end of it clenching and unclenching with a snapping sound.

At that point they burst from the tunnel, and almost instantly plunged into a golden-yellow sky-sea. Its light poured in through the screen.

Behind them, another leg broke through, and another, sawing away frantically.

Itharquell raised his hands in a gesture of despair. He pressed a control and a section of wall irised open in front of them. Golden light poured through. Without hesitation, Itharquell leapt out.

Sam stood on the threshold, looking down. Logic dictated that, if she stepped out of the dirigible, she would fall for ever. But logic could b.u.g.g.e.r off. Taking a deep breath, she leapt into s.p.a.ce.

Sam gasped as the golden sky-sea enveloped her. It was like that feeling you get when you sink into a hot bath, that almost s.e.xual frisson which makes you gulp and gasp in pleasure.

She hung there for a second, and then flexed her arms experimentally. Surprisingly, she moved quite a way. Below her, she saw Itharquell swimming? flying? like a fish? a bird? swimming? flying? like a fish? a bird? falling down and down until he was a dot. falling down and down until he was a dot.

She looked back. And gasped.

Three Ruin were tearing the dirigible apart, placing the pieces daintily in their bell-shaped bodies, cilia waving about in obvious pleasure. They seemed not to notice her. But it wouldn't be long before they had consumed the entire dirigible. What was it Itharquell said the things did? Laid their eggs inside you?'

'Sorry guys,' Sam whispered to herself. 'That's not the way Sam Jones is gonna go.' And, jerking her arms and legs in a swimming motion, Sam set off in the direction Itharquell had taken.

Chapter Thirteen.

So Fast, So Numb Fitz stood aside, letting the soldiers past. The Doctor hadn't even noticed him. Gesturing to Kerstin, he followed. The soldiers took the Doctor off left into a corridor which looked less well cared for than the rest. The walls were of bare breeze block, the concrete floor dusty. Pale light came from circular lamps fixed to the walls.

The soldiers stopped outside a metal door, the Doctor held firmly between them. Fitz tensed. Should he risk rushing them? No there were two of them, and they were probably very fit and highly trained. As he deliberated, the soldiers opened the door and disappeared inside with the Doctor. The door closed behind them with a hefty thump.

Fitz tried the door; the metal handle would not budge. Then it began to open and he jumped back, b.u.mping into Kerstin. He saw an open door further down the corridor, on the opposite side, and grabbed her, almost dragging her along the corridor. They ducked inside, Fitz closing the door behind them. They seemed to be in some sort of storeroom, lined with cluttered metal shelving.

Kerstin removed her helmet and tossed it into a corner. She still had that chilling dead expression, as if nothing mattered to her. 'I'm not wearing that thing any more,' she said dully. 'Let them catch us.'

Fitz also removed his helmet, glad to be free from its confinement for a while. 'Kerstin, don't give up!'

Kerstin put her head in her hands and burst into tears, rocking back and forth on her haunches. She muttered something in Swedish.

It was too late. She had given up. She was in no state to cope with anything. What she needed was a dose of tranquillisers, a few days in bed, and time to come to terms with her loss. None of which Fitz could provide. All he had was words, and he knew from personal experience how useless they could be. Kerstin had to go through her grief, and there was nothing he could really do to help. All he could do was drag her through this and hope they both got out the other side in one piece.

Fitz swallowed hard. He had to rescue the Doctor. Act the hero again. He wasn't cut out for this sort of thing at all. What if he was captured? Or shot? What if he only made things worse for the Doctor? Fitz pushed such thoughts to the back of his mind. Once the Doctor was free, he'd sort everything out, right? Right... He remembered the Doctor in the farmhouse, after Bjorn had died. He'd seemed weird, not all there. What had he said? Without the TARDIS he was incomplete?

He sighed, and went over to Kerstin, sitting down beside her and putting an arm around her shoulders. The human contact made him feel a little better but probably did nothing for her. Her face was blotched and red, her eyes gleaming with tears.

'Look, I've got to try to rescue the Doctor,' he murmured, looking around at the shelves for anything he could use as a weapon, but there was nothing.

Kerstin gave no sign of hearing him. He hated to leave her like this, but he had no choice. He stood up, put his helmet on and opened the door.

To his left, the corridor was empty. To his right, footsteps.

He ducked back into the store room, holding the door to. From outside, the footsteps became louder. Fitz frowned. These weren't the clump of soldiers' boots, but the tap-taptap of stiletto heels. He heard the door opposite click open.

Fitz emerged into the corridor, not sure what to do. Someone had gone into the room. A nurse maybe? Someone with food for the Doctor? The door was ajar, and closing slowly. In a few seconds it would slam locked shut again. He nipped down the corridor and caught the door just before it closed, slipping inside.

The room he found himself in was small and boxlike, dimly lit by a soft yellow lamp in the rear wall. Its main feature was a picture window which ran the whole length of the room. In front of this sat a woman in a lab coat, staring through the window into a tastefully furnished lounge. There was the Doctor, sitting on the sofa, nursing a pink cushion. Fitz's heart gave a surge of joy at the sight. Then he realised that the woman had swivelled her chair round to stare at him.

She had long dark hair tied back in a ponytail, and her face was serious, pale. She wore round gla.s.ses. 'Who the h.e.l.l are you?' she said; her voice had an American accent.

Fitz froze to the spot, racking his brain for a lie that would explain why he was here. He had no idea who this woman was, what role she was playing in whatever was going on here, what reason for his presence would satisfy her.

Fitz waved a gloved hand. 'I'm, er, I've come to check on the prisoner.'

Her mouth hardened in a tight line, and she stood up. She wasn't very tall, but her eyes were hard as stone. 'Can't you guys leave him alone for five minutes?'

Fitz backed away from her.

She gestured to the Doctor, who was now lying on the sofa. 'Can't you see he's had enough of all this bulls.h.i.t?'

Fitz could. The Doctor looked washed out, miserable. 'Yes, you're right.'

The woman prodded Fitz in the chest. 'So go away and leave us.'

Despite her sharp fingernails, and sharper tongue, this woman posed no great threat. Fitz whipped his helmet off and flashed her his most disarming smile. 'h.e.l.lo. I'm a friend of the Doctor's and therefore at least as interested in his welfare as you are.'

The woman looked stunned for a moment. She opened her mouth to speak, then closed it again. 'Hey, you're not one of Wolstencroft's men. Or anyone else I know.' She was backing towards the desk.

Any number of those b.u.t.tons could call for help, so Fitz dodged round her, placing himself between her and the desk. 'I've come to get the Doctor out of here,' he said, trying to sound as determined as possible. 'And you're going to help me.'

She folded her arms. 'Look, just exactly who are you?'

Fitz sighed. There was no point in lying. 'I'm Fitz Kreiner. Like I said, I'm a friend of the Doctor's.'

Realisation dawned in her eyes. 'He mentioned someone called Fitz.'

'Yes, he would,' said Fitz, agitatedly. 'Look, are you going to help me set him free?'

She laughed. 'Yeah, right. This place is under martial law now. Freeing the Doctor is about the best way to get shot.'

'All right, I'll do it myself.' Fitz turned to the interior door, trying the handle. It was locked. He went to the desk.

The woman sighed. 'I guess you're not going to go away. It's the yellow b.u.t.ton to the left of the monitor.'

Fitz pressed the b.u.t.ton.

'I'm Professor Jennifer Nagle,' said the woman, walking over to the interior door. 'Excuse my manners but I don't get out much these days.'

She opened the door and gestured Fitz through.

The Doctor stood up, a look of amazement on his face, and then to Fitz's considerable surprise he bounded over, grabbed his head and planted a kiss squarely on his lips. 'Oh, Fitz! Fitz, Fitz, Fitz! I'm so glad you're alive!'

Fitz staggered back, overwhelmed. 'Glad to see you too,' he murmured, feeling himself blushing under Professor Nagle's stare of amazement and mirth. 'Now, would someone mind telling me what the h.e.l.l is going on here?'

The Doctor's face was suddenly serious again. It was as if the sun had gone behind a thundercloud. 'Dangerous experiments with the fabric of reality,' he said, glaring at Nagle, who stared back defiantly.

'That's fine, then,' said Fitz, none the wiser.

The Doctor raised his eyebrows. 'This woman is responsible for what happened to the TARDIS and Sam.'

'Hey now, hang on there,' said Nagle, raising her hands and backing away from both of them.

Fitz scowled at her. 'How is she responsible?'

The Doctor spoke quickly, the words tumbling over each other. 'She's inadvertently created a large and unstable wormhole which has attached itself to an extradimensional anomaly causing spatial and hyperspatial distortion '

Fitz held up a hand. 'All right! All right!'

The Doctor stopped speaking and looked at Fitz sheepishly.

'All I want to know is is Sam alive and can we get her back?'

The Doctor pulled a face. 'I don't know,' he said simply. 'But I'm going to try. Come on.'

Professor Nagle was still wearing a wide-eyed expression of fright.

'Don't worry, we won't hurt you,' said the Doctor as he walked past her.

True enough, thought Fitz, following the Doctor out into the corridor, his mind cartwheeling to catch up with events. Oddly he felt no anger towards Professor Nagle. She didn't seem evil. Whatever had happened in the TARDIS was obviously an accident.

Then he thought of Kerstin. Professor Nagle was responsible for the death of Johan. He had to keep that from her.

'Doctor,' he said, tapping his shoulder.

The Doctor turned round, a cross expression on his face. 'Yes?'

'Um, I've got someone else with me.'

Kerstin was nowhere. She was nothing. To stop herself from screaming, to stop her heart from dragging in her chest like a dead thing, she imagined herself at the bottom of the lake, where no light could reach her, where the pressure of the water kept everything away from her. An endless darkness.

She remembered another lake, back when she was a child, where her mother was teaching her to swim. She remembered the feeling of elation when she floated away from her mother's hands. I can do it, I can swim, I don't need anyone to support me.

Now she was sinking. And there was no one there to catch her. This was good. She didn't want anyone to catch her. She wanted to fall and fall until she hit the bottom.

She wanted to die.

To die?

She opened her eyes, and stared at the wall in front of her. Her head felt fuzzy, as if she had a bad cold. Now she had let out the pain, she felt calmer, and could a.n.a.lyse her feelings. Did she really want to die? Did the death of Johan matter so much?

Yes it did matter. She could still see those those things breaking out of his flesh, the blood, the unutterable agony on his face as he died. And then in the mortuary the body she had loved, the body that had loved her, taken apart like some fleshly machine, something that had never held life or love or swum in the lake with her at midnight.

She looked around, realising for the first time that Fitz had gone. Fitz. She didn't quite know what to make of him. He seemed concerned in the usual useless male way. But all this talk of time machines? Could it be true? She almost laughed out loud; it was too ridiculous, too far-fetched.

Too much to hope for. Because if Fitz was telling the truth, if the Doctor did have a time machine, he could take her back, to before. To when Johan was alive.

They could be together again. Could she save him? Was that possible?

She stood up, unzipping her encounter suit and climbing out of it. She inspected herself: grazed knees from the flight through the forest and mud on her shorts and trainers. She didn't want to think what a mess her face looked and didn't really care.

She walked slowly around the room, looking at the items on the shelves without interest. The door banged open and Fitz appeared, still in his crumpled white encounter suit. The Doctor stood behind him, as did a woman in a white lab coat, with her arms folded.

Fitz seemed to be more relaxed now that the Doctor was there. 'I um are you all right now?' he said lamely.

Kerstin ignored the ba.n.a.lity of the question and tried to smile, the muscles of her face aching and her eyes feeling swollen. 'As all right as I'll ever be.'

The Doctor pushed past Fitz. His eyes were full of compa.s.sion, and devoid of fear. Despite everything, Kerstin felt a wave of calmness wash over her.

'Kerstin,' said the Doctor. 'I know you have been through a lot, but I promise you it will all be over soon. Everything will be all right.'

He spoke quickly, in a cultured, lilting voice. Although his words were ba.n.a.l, she found herself believing him. 'Just get me out of here,' she whispered.

He smiled sadly. 'I promise you, you'll get out of here.'

She stared into his eyes, large and blue and full of the sadness of wisdom, and something changed within her. She suddenly believed all that Fitz had said but out of Fitz's mouth, looking into Fitz's shifty eyes, it had all seemed a crazy fantasy. Now, looking into the Doctor's eyes, she knew that this was a man who travelled in time, who fought monsters both alien and human and usually won.

He could take her back. Kerstin's head swam. He could take her back. He could make it all right again. At all costs, she had to stick with the Doctor.

'We haven't got time for this,' said the woman, and the spell was broken.

'Come on, Doctor,' said Fitz.

The next few minutes were a blur. She followed the Doctor, Fitz and the woman in the lab coat along the white corridor and past the lifts. Fitz was no longer wearing his helmet, and his face was pale and sweaty. Soldiers and white-suited scientists bustled past, ignoring them.

Kerstin yearned for explanations, but she told herself to be patient. She was rushing headlong into the heart of the mystery, and soon she would know everything. She felt a surge of excitement which was brought crashing down as the image of Johan's white body popped back into her mind with devastating force.

Knowing everything anything wasn't worth it.